The present disclosure relates methods of making to a burnthrough resistant non-woven mat, and in particular to a lightweight burnthrough resistant non-woven mat for use in thermal and acoustical insulation blankets used in commercial aircraft and in other applications requiring burn through resistance properties of the type or similar to those properties currently required for commercial aircraft.
Commercial aircraft manufacturers and aircraft regulatory agencies in the United States have established combined thermal, acoustical, component and composite small scale flammability, fire barrier, fire propagation, smoke toxicity, moisture management, weight, fabricate-ability, health and cost requirements for insulation blankets. In particular, the Federal Aviation Administration (FAA) insulation burnthrough test is defined at www.fire.tc.faa.gov and by the test method to evaluate the burnthrough resistance characteristics of aircraft thermal/acoustic insulation materials when exposed to a high intensity open flame provided in §25.856 and 14 C.F.R. §25, Appendix F, Part VII and Advisory Circular 25.856-2A. The fire penetration resistance requirements of thermal/acoustic insulation used in transport category airplanes manufactured after Sep. 2, 2007, became effective Sep. 2, 2009.
U.S. Pat. No. 6,884,321 discloses a flame and heat resistant paper having high burnthrough prevention capability and prepared from modified aluminum oxide silica fibers, in addition to other components. While U.S. Pat. No. 6,884,321 discloses that the basis weight of the paper may range from about 5 to about 250 lb/3000 ft2 (i.e., about 5 to about 250 pounds per ream), U.S. Pat. No. 6,884,321 also discloses that a paper as light as 5 pounds per ream may not pass burnthrough requirements, and that it may be advantageous to use multiple layers of a very thin lightweight paper, and that air space between such layers may prove desirable, for example, in the heat flux portion of the burnthrough test.
There remains a need for a lightweight aircraft blanket that responds to and meets all of the regulatory, aircraft manufacturer and aircraft operator requirements and expectations. The burnthrough resistant non-woven mat set forth in this patent application allows for assembly of such a lightweight blanket.